OTTAWA—The Competition Bureau says criminal charges have been laid against four people who allegedly conspired to rig bids for 21 City of Gatineau infrastructure contracts between 2004 and 2008.

The bureau alleges the four, who worked for engineering firms, divided the contracts awarded by the City of Gatineau among themselves.

The regulator alleges the firms secretly fixed prices submitted in response to City of Gatineau calls for tenders at, or near, a tariff schedule established by the Association des ingenieurs-conseils du Quebec.

The allegations have not been proven in court.

The City of Gatineau was not aware of the alleged bid-rigging scheme, the bureau says.